The invention relates to working vehicles such as wheel loaders, baggers or floor-level conveyor vehicles, whose driving direction during work changes at short time intervals and which frequently have to be driven backward.
This frequent driving direction change is also known as reversing. In this, the vehicle moving at full driving speed in a forward driving direction is braked by engaging the reverse gear and then accelerated in a backward driving direction.
The vehicle's change of driving direction begins with the opening of the driving direction clutch of the existing driving direction and the closing of the driving direction clutch of the new driving direction. During this change, the turbine side of the hydrodynamic torque converter is slowed down or made to reverse its rotation direction, depending on the force transfer of the forward or backward driving clutch. During this, the pump side of the hydrodynamic torque converter is supported by the drive engine. The deceleration and acceleration times of the vehicle can be influenced by the power of the drive engine, the characteristics of the hydrodynamic torque converter and the slippage time of the driving direction clutches. However, this is only possible in limited measure, since the extent to which the driving direction clutches can be loaded is limited.
DE 30 23 278 C2 discloses a method for the control of a force transfer mechanism, in which the deceleration time is influenced by changing the transmission ratio of the speed-shift transmission when changing the driving direction. It is not possible to change between the driving direction clutches at a high speed.
The purpose of the present invention is to provide a method for controlling a drive train in which frequent driving direction changes, even from high driving speeds are possible and the deceleration and acceleration times can be influenced according to need.